I had this problem and this is what I found to be the easiest fix:
Just navigate to the root of your installation drive then go to:
Library/Preferences/SystemConfiguration/
and delete: NetworkInterfaces.plist
(and make a secure copy somewhere else if you are sceptical!).
Reboot
Should be working now.
(I spent ages over this problem, scoured the Internet trying different resolutions... But this is the safest and easiest!)
YES!!!!! THANK YOU SO MUCH!!! I've been looking for the last 2 weeks with no results all over the internet. Thanks again!
This should still work for Mountain Lion:
http://hacksbyalfa.com/post/14499097009/10-7-1-icloud-app-store-itunes-match-all-fixed
Good luck!
This should still work for Mountain Lion:
http://hacksbyalfa.com/post/14499097009/10-7-1-icloud-app-store-itunes-match-all-fixed
Good luck!